Knowledge and awareness of hepatitis B among households in Malaysia: a community-based cross-sectional survey

Background Hepatitis B (HepB) is a major public health concern in Malaysia yet little is known about knowledge and awareness of this infection in the country. Such information is essential for designing effective intervention strategies for HepB prevention and control. The aim of this study was to characterize knowledge and awareness regarding HepB in Malaysia and to identify their associated sociodemographic determinants. Methods A community-based cross-sectional survey was conducted between January and May 2016 in Selangor state of Malaysia. A two-stage cluster random sampling design was used and one adult member of selected households was interviewed face-to-face. Logistic regression was used to estimate the differences in knowledge and awareness between groups. Results A total of 764 households completed the interviews and were included in the final analysis. Only 36.9 and 38.8% of the participants had good knowledge and awareness, respectively. The factors associated with good knowledge were being in the 35–44 year age group, Malay ethnicity, high educational attainment and high family income. Being Chinese, being older and having high educational attainment were determinants of having good awareness towards HepB. Participants who had good knowledge were 2.5 times more likely to also have good awareness (OR: 2.41, 95% CI: 1.78–3.26, p < 0.001). Conclusions This study reveals a low level of knowledge and awareness of HepB among households in Malaysia. This finding highlights the need to improve public knowledge and awareness through well-designed programs targeting vulnerable groups in order to reduce hepatitis B virus transmission and achieve the governmental target of eliminating viral hepatitis as a public health concern by 2030. Electronic supplementary material The online version of this article (10.1186/s12889-018-6375-8) contains supplementary material, which is available to authorized users.


Introduction
Background/rationale 2 Explain the scientific background and rationale for the investigation being reported We provided specific background that hepatitis B (HepB) is prevalent in Malaysian but the data related to knowledge and awareness among Malaysians is very limited. This knowledge is important for used to design intervention strategies at a national scale and to develop an effective HepB prevention program. Therefore, this study was conducted to provide more comprehensive data related to knowledge and awareness in Malaysia.

Background
Objectives 3 State specific objectives, including any prespecified hypotheses (N/A) "The aim of this study was to assess the knowledge and awareness of HepB and to identify associated sociodemographic determinants among representative community members in Malaysia."

Methods: Study variables
Data sources/ measurement 8* For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group.
Interest variables (included explanatory and response variables) were assessed by interviews. The differences of the mean score of knowledge and awareness between explanatory variables were analyzed using Analysis of Variance (ANOVA) and a multi-step logistic regression analysis.

Methods: Data collection & Statistical analysis
Bias 9 Describe any efforts to address potential sources of bias During interview, the correct answers to the survey questions were not provided to interviewers. In addition, confounding factors were explored between the adjusted odds ratio (aOR) in multivariate analyses and the crude odds ratio (OR) in univariate analyses using strategy that have been described previously.  (25-34, 35-44, 45-54 and 55 years old or above). For employment status, five general types were used for classification: public sector, private sector, self-employment, student or university student and retired. Participants who had an unclassified job were grouped as others, and participants who had no job currently were listed as unemployed." Response variables (knowledge and awareness towards HepB) was assessed using a scoring system. For statistical analysis, the knowledge and awareness domains were dichotomized into "good" and "poor" based on a 75% cut-off point. These processes resulted all variables become quantitative and therefore suitable for further analyses.

Methods: Explanatory variables & Statistical analysis
Statistical methods 12 (a) Describe all statistical methods, including those used to control for confounding "The differences of the mean score of knowledge and awareness between explanatory variables were analyzed using Analysis of Variance (ANOVA)". "To assess the association between the explanatory variables and the response variables, a multi-step logistic regression analysis was employed." Methods: Statistical analysis

(b) Describe any methods used to examine subgroups and interactions In this study, "the correlation between scores of knowledge and awareness was assessed using Spearman`s rank correlation (rs) based on the Kolmogorov-Smirnov normality test."
Methods: Statistical analysis (c) Explain how missing data were addressed In this study, we only included data of participants who provided or completed all section of the questionnaire. All participants with missing data were excluded from analyses.

Methods: Statistical analysis (e) Describe any sensitivity analyses
There is no any sensitivity analysis relevant to this study. However, we did questionnaire validity test to assess the internal consistency of the questionnaire prior used in the study.

Results
Participants 13* (a) Report numbers of individuals at each stage of study-eg numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up (N/A), and analysed. "In this study, 768 respondents were interviewed and four responses were excluded due to incomplete information leaving a dataset with a total of 764 (99.4%) participants".
Results: Socio demographic characteristics (b) Give reasons for non-participation at each stage In this study, the non-participant occurred in one stage only which was incomplete data during data collection. All incomplete data from participants were excluded from the analysis.

Results: Socio demographic characteristics
(c) Consider use of a flow diagram Descriptive data 14* (a) Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential confounders In this study, characteristics of study participants are summarized Results: Socio demographic characteristics. We included a very little information of the Table 1 into description text to avoid repetitive.

Results: Socio demographic characteristics
(b) Indicate number of participants with missing data for each variable of interest In this study, we only included data of participants who provided or completed all section of the questionnaire. Meaning that each variable of interest had the same number of participants.

Results: Socio demographic characteristics
Outcome data 15* Report numbers of outcome events or summary measures The knowledge and awareness domains were dichotomized into "good" and "poor" based on a 75% cut-off point

Subheading of article
Main results 16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included.
In this study, unadjusted estimates (univariate analysis) and adjusted estimates are calculated for each explanatory and response variable and both of them provided in Table 1 and 2 for knowledge and awareness, respectively.